Genome Instability In Fruit Body Derived Lines Generated From Fruiting Pfle Somatic Hybrid Lines And Development Of Hybrid Strain Specific Scar Marker In Edible Mushroom

Six fruit body derived lines (pfle FB) generated from six fruiting pfle somatic hybrid mushroom lines showed genetic diversity analysed by fruit body morphology and inter simple sequence repeat (ISSR) markers. Stipe length, pelius diameter and bioefficiency % (BE%) of all the strains showed variations between each other with respect to Pleurotus florida parent. Hybrid pfle 1v and pfle 1q showed the highest value of stipe length and pelius diameter, respectively, compared with parent P. florida. Four ISSR primers amplified a total of 47 reproducible fragments with 82.9% polymorphism in which primer ISSR-03 produced the highest number of amplicons. Unweighted pair group method with arithmetic mean (UPGMA) based dendrogram exhibited two major groups in which hybrids pfle 1r and pfle 1q showed genetical closeness to parents P. florida and Lentinula edodes, respectively. Tissue culture generated line from fruit body of pfle 1r hybrid showed maximum BE% compared with the other hybrids and P. florida parent. For identification of this line, a pair of hybrid strain-specific SCAR marker (RFB2F and RFB2R) was developed based on an unique 813 bp RAPD amplicon

Influence of the Physiological Age and Position of the Nodal Explants on Micropropagation of Field-Grown Dendrocalamus Strictus Nees

An efficient and reproducible protocol for plant regeneration through in vitro culture of Dendrocalamus strictus is reported. Murashige and Skoog\u27s (MS) basal medium supplemented with N6-benzyladenine and adenine sulphate resulted in high frequency of shoot organogenesis. Nodal explants obtained from mature field-grown culms of selected elite genotype of D. strictus produced multiple shoots. Percent regeneration and number of multiple shoots was directly correlated with the nodal segments from which explants were collected. Best regeneration response was noted from 1st and 2nd positions from the basal end of the secondary branches. The effect of physiological age of the donor plant on axillary shoot multiplication was studied for three consecutive years. The regeneration frequency declined with the maturity of the donor plant. Roots and monopodial type micro-rhizomes were induced in medium containing half strength of MS macrosalts supplemented with indole-3-butyric acid and regenerants were successfully transplanted in the soil. © 2004 Society for Biology and Biotechnology

Identification of Genes Involved in Wild Crucifer <i>Rorippa indica</i> Resistance Response on Mustard Aphid <i>Lipaphis erysimi</i> Challenge

<div><p>Mustard aphid, <i>Lipaphis erysimi</i> (L.) Kaltenbach is a perpetual annual threat in the cultivation of rapeseed- mustard (<i>Brassica spp</i>.) crop in tropical and sub-tropical climate. Cultivated <i>Brassica</i> germplasm has failed so far to provide any source of resistance. Wild germplasm is a potential source of resistance against many threatening herbivores. On wild germplasm screening, we noted that the wild crucifer <i>Rorippa indica</i> (L.) Hiern confers resistance against <i>L. erysimi</i>. In the present study <i>L. erysimi</i> challenged transcriptome of <i>R. indica</i> was compared to un-infested <i>R. indica</i> sample to get a molecular insight about the aphid resistance mechanism and identify the candidate defense response genes. Cloning, sequencing and <i>in silico</i> sequence analysis of complimentary DNA amplified fragment length polymorphism identified 116 differentially expressed transcript derived fragments revealed thirty candidates which are from different functional categories including redox regulation, signalling, photosynthesis, structure, metabolism, defense response as well as a few of unknown function. Twenty four identifications were then studied by quantitative real time RT PCR analysis at 6, 12, 24 and 48 hour time point post infestation to understand the early-to-late defense response through their relative gene expression profiles. Seventeen fragments showed significant up or down regulation at p<0.05 level. The response was influenced by different phytohormonal signalling pathways simultaneously. The candidate defense response expressed sequence tags specifically for the resistance genes identified in this study have implication in building desired mustard aphid resistance in susceptible rapeseed-mustard plants in future. This is the first molecular report on crucifer defense response against mustard aphid <i>L. erysimi</i>.</p></div

Exploring Genetic and Epigenetic Changes in Lingonberry Using Molecular Markers: Implications for Clonal Propagation

Lingonberry (Vaccinium vitis-idaea L.) is an important and valuable horticultural crop due to its high antioxidant properties. Plant tissue culture is an advanced propagation system employed in horticultural crops. However, the progeny derived using this technique may not be true-to-type. In order to obtain the maximum return of any agricultural enterprise, uniformity of planting materials is necessary, which sometimes is not achieved due to genetic and epigenetic instabilities under in vitro culture. Therefore, we analyzed morphological traits and genetic and epigenetic variations under tissue-culture and greenhouse conditions in lingonberry using molecular markers. Leaf length and leaf width under greenhouse conditions and shoot number per explant, shoot height and shoot vigor under in vitro conditions were higher in hybrid H1 compared to the cultivar Erntedank. Clonal fidelity study using one expressed sequence tag (EST)—polymerase chain reaction (PCR), five EST—simple sequence repeat (SSR) and six genomic (G)—SSR markers revealed monomorphic bands in micropropagated shoots and plants in lingonberry hybrid H1 and cultivar Erntedank conforming genetic integrity. Epigenetic variation was studied by quantifying cytosine methylation using a methylation-sensitive amplification polymorphism (MSAP) technique. DNA methylation ranged from 32% in greenhouse-grown hybrid H1 to 44% in cultivar Erntedank under a tissue culture system. Although total methylation was higher in in vitro grown shoots, fully methylated bands were observed more in the greenhouse-grown plants. On the contrary, hemimethylated DNA bands were more prominent in tissue culture conditions as compared to the greenhouse-grown plants. The study conclude that lingonberry maintains its genetic integrity but undergoes variable epigenetic changes during in vitro and ex vitro conditions

Time course aphid infestation study.

<p>Record of the mean number of aphids at different time points post infestation with <i>L. erysimi</i> on <i>R. indica</i>. Aphid colonization peaks at around 24 hpi and falls sharply by 48 to 72 hpi. Error bars represent standard error of the mean (n = 5). ‘*’, ‘**’ and ‘***’ indicate the level of significance of the noted number of aphids at significance level of p<0.05.</p

Time course relative gene expression analysis.

<p>Time course relative expression (Y-axis) level profiles of 24 genes induced in <i>R. indica</i> on forced infestation with <i>L. erysimi</i> (as identified by cDNA AFLP with respect to uninfested plants) at different time points viz. 6, 12, 24, 48 hours post infestation (X-axis), as analysed quantitative real time RT PCR analysis. The genes have been represented under different functional categories. Error bars represent standard error of the mean (n = 3). ‘*’, ‘**’ and ‘***’ indicate the level of significance of the relative gene expression level noted at the significance level of p<0.05.</p

The candidate resistance response TDFs identified in the transcriptomic analysis of <i>R. indica- L. erysimi</i> interaction.

<p>The candidate resistance response TDFs identified in the transcriptomic analysis of <i>R. indica- L. erysimi</i> interaction.</p

Epigenomic insight of lingonberry and health-promoting traits during micropropagation

Abstract Epigenetic variation plays a role in developmental gene regulation and responses to the environment. An efficient interaction of zeatin-induced cytosine methylation and secondary compounds has been displayed for the first time in tissue-culture shoots/plants of lingonberry (Vaccinium vitis-idaea L.) cultivar Erntedank in vitro (NC1, in a liquid medium; NC2, on a semi-solid medium), ex vitro (NC3, node culture-derived plants; LC1, leaf culture-derived plants) and its cutting-propagated (ED) plants. Through methylation-sensitive amplification polymorphism (MSAP) assay, we observed highest methylated sites in leaf regenerants (LC1) from all primer combinations (108 bands), along with the highest secondary metabolites. The four types of tissue culture-derived shoots/plants (NC1, NC2, NC3, LC1) showed higher methylation bands than cutting propagated donor plants (ED) that exhibited 79 bands of methylation, which is comparatively low. Our study showed more methylation in micropropagated shoots/plants than those derived from ED plants. On the contrary, we observed higher secondary metabolites in ED plants but comparatively less in micropropagated shoots (NC1, NC2) and plants (NC3, LC1)